Measuring self-steepening with the photon-conserving nonlinear Schrödinger equation

Area of Science:

• Nonlinear optics
• Waveguide optics
• Quantum optics

Background:

• Self-steepening (SS) is a crucial nonlinear optical effect in pulse propagation.
• Existing methods for measuring SS can be complex or indirect.
• The photon-conserving nonlinear Schrödinger equation (NLSE) provides a new theoretical framework.

Purpose of the Study:

• To introduce a simple, direct, and original method for measuring self-steepening (SS) in nonlinear waveguides.
• To validate the proposed method against analytical models and numerical simulations.
• To demonstrate the robustness of the method under realistic experimental conditions.

Main Methods:

• Utilizing the time shift experienced by soliton-like pulses due to SS.
• Directly measuring this pulse time shift to estimate the SS parameter.
• Comparing the proposed method with the standard NLSE approach.

Main Results:

• The proposed method accurately estimates the SS parameter through direct time shift measurement.
• Numerical simulations confirm excellent agreement with the analytical model.
• The technique is validated across near-infrared, telecommunication, and mid-infrared spectral regions.

Conclusions:

• The developed method provides a precise and straightforward way to quantify self-steepening in nonlinear waveguides.
• The approach is robust against variations in pulse shape, power, width, and higher-order dispersion.
• This technique offers a significant advancement for characterizing nonlinear optical phenomena.